cpufreq: Make sure target freq is within limits

__cpufreq_driver_target() must not pass target frequency beyond the
limits of current policy.

Today most of cpufreq platform drivers are doing this check in their
target routines. Why not move it to __cpufreq_driver_target()?

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 28dc134cec36..2f5ac2dcfda6 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1470,12 +1470,19 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
                             unsigned int relation)
 {
         int retval = -EINVAL;
+        unsigned int old_target_freq = target_freq;
 
         if (cpufreq_disabled())
                 return -ENODEV;
 
-        pr_debug("target for CPU %u: %u kHz, relation %u\n", policy->cpu,
-                target_freq, relation);
+        /* Make sure that target_freq is within supported range */
+        if (target_freq > policy->max)
+                target_freq = policy->max;
+        if (target_freq < policy->min)
+                target_freq = policy->min;
+
+        pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
+                        policy->cpu, target_freq, relation, old_target_freq);
 
         if (target_freq == policy->cur)
                 return 0;